Oedignatha zham, Zhang & Mu & Zhang, 2025

Oedignatha zham sp. nov.

Figs 5–8 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8

Type material. Holotype ♂ (MHBUARA-2023-901-1), CHINA: Xizang Autonomous Region: Nyalam County, Zham Town ( 27.9682°N, 85.9724°E; 2352 m a.s.l.), 10.VIII.2023, leg. X. Guo, H. Zhang. GoogleMaps Paratype: 1♀ (MHBUARA-2023-901-2), same data as holotype GoogleMaps .

Etymology. The specific epithet is derived from the name of the type locality, noun in apposition.

Diagnosis. Males of O. zham sp. nov. are most similar to the males of O. platnicki Song & Zhu, 1998 in having a similar shaped retrolateral tibial apophysis and a distally sclerotized conductor, but can be distinguished by: 1) the retrolateral branch of the retrolateral tibial apophysis with an apical bifurcation ( Figs 6C View FIGURE 6 , 8C View FIGURE 8 ; vs. two tooth-like projections in O. platnicki , see Chen & Huang 2009: fig. 9); and 2) conductor with a blunt apex directed at 11-o’clock ventrally ( Figs 6B View FIGURE 6 , 8B View FIGURE 8 ; vs. angular apex directed at 2-o’clock ventrally in O. platnicki , see Song & Zhu 1998: fig. 2E, Chen & Huang 2009: fig. 8). Females resemble O. shaanxi in having short copulatory ducts and spherical bursae, but can be distinguished from the latter by: 1) the epigynal plate with a septum ( Figs 7A View FIGURE 7 , 8D View FIGURE 8 ; vs. without septum in O. shaanxi , see Chu et al. 2023a: fig. 2A); and 2) spermathecae small and oval ( Figs 7B View FIGURE 7 , 8E View FIGURE 8 ; vs. large and spherical in O. shaanxi , see Chu et al. 2023a: fig. 2B).

Description. Male ( holotype, Figs 5A–B View FIGURE 5 ). Total length 7.00, carapace 3.61 long, 2.59 wide; abdomen 3.39 long, 2.04 wide. Carapace oval, reddish-brown. Cervical and radial grooves indistinct. Clypeal hump inconspicuous ( Fig. 5A View FIGURE 5 ). Labium and endite reddish-brown. Sternum medially reddish-brown, marginally brown ( Fig. 5B View FIGURE 5 ). Legs brown, distal ends of femora of legs Ⅰ and IV yellow. Chelicerae with three pro- and seven retromarginal teeth, basal retromarginal tooth bifurcated. Eye sizes and interdistances: AME 0.14, ALE 0.14, PME 0.10, PLE 0.11; AME–AME 0.22, AME–ALE 0.28, ALE–ALE 0.84, PME–PME 0.39, PME–PLE 0.29, PLE–PLE 1.19, ALE–PLE 0.13. Leg measurements: Ⅰ 11.44 (2.91, 1.17, 2.77, 2.80, 1.79), II 9.36 (2.59, 1.03, 2.13, 2.22, 1.39), III 8.08 (2.22, 0.91, 1.56, 2.11, 1.28), IV 11.32 (2.88, 1.04, 2.38, 3.17, 1.85); leg formula 1423. Tibial and metatarsal ventral spines depicted in Table 2. Abdomen oval, dorsum dark brown, dorsal scutum covering approximately 5/6 of abdomen ( Fig. 5A View FIGURE 5 ).

Palp ( Figs 6 View FIGURE 6 , 8A–C View FIGURE 8 ). Cymbium basoretrolaterally with shallow groove extending about 1/4 length of cymbium

( Figs 6C View FIGURE 6 , 8C View FIGURE 8 ). Retrolateral tibial apophysis with two branches, prolateral branch hook-shaped, pointing anteriorly in ventral view, retrolateral branch broad, apically bifurcated, higher sclerotization than prolateral branch ( Figs 6C View FIGURE 6 , 8C View FIGURE 8 ). Conductor beak-shaped in retrolateral view, with broad base and angular tip ( Figs 6C View FIGURE 6 , 8C View FIGURE 8 ). Embolus filamentous, originating from 6-o’clock position and extending clockwise to anterior part of conductor in ventral view ( Figs 6B View FIGURE 6 , 8B View FIGURE 8 ).

Female ( paratype, Figs 5C–D View FIGURE 5 ). Same as male except for the following: total length 7.31, carapace 3.41 long, 2.41 wide; abdomen 3.90 long, 2.56 wide. Chelicerae with eight retromarginal teeth, basal tooth not bifurcated. Eye sizes and interdistances: AME 0.12, ALE 0.13, PME 0.09, PLE 0.11; AME – AME 0.17, AME – ALE 0.14, ALE – ALE 0.68, PME – PME 0.31, PME – PLE 0.28, PLE – PLE 1.04 , ALE – PLE 0.14. Leg measurements: Ⅰ 10.99 (2.79, 1.03, 2.80, 2.76, 1.61), II 9.04 (2.47, 1.03, 1.93, 2.19, 1.42), III 8.00 (2.16, 0.92, 1.48, 2.11, 1.33), IV 10.92 (2.56, 0.94, 2.50, 3.11, 1.81). Tibial and metatarsal ventral spines depicted in Table 2. Abdomen oval, with incomplete dorsal scutum ( Fig. 5C View FIGURE 5 ) .

Genitalia ( Figs 7 View FIGURE 7 , 8D–E View FIGURE 8 ). Epigynal plate sclerotized, with trapezoidal and membranous epigynal window divided medially by septum ( Figs 7A View FIGURE 7 , 8D View FIGURE 8 ). Copulatory ducts short and arched. Bursae globular. Spermathecae oval. Fertilization ducts narrow, roughly anteriad ( Figs 7B View FIGURE 7 , 8E View FIGURE 8 ).

Distribution. Known only from the type locality.